================================================================== BUG: KASAN: use-after-free in ax25_heartbeat_expiry+0x10c/0x130 net/ax25/ax25_timer.c:125 Read of size 4 at addr ffff888022d8f550 by task syz-executor/4189 CPU: 0 PID: 4189 Comm: syz-executor Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 print_address_description+0x60/0x2d0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0xdf/0x130 mm/kasan/report.c:451 ax25_heartbeat_expiry+0x10c/0x130 net/ax25/ax25_timer.c:125 call_timer_fn+0x17b/0x540 kernel/time/timer.c:1648 expire_timers kernel/time/timer.c:1699 [inline] __run_timers+0x53e/0x800 kernel/time/timer.c:1970 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1983 handle_softirqs+0x339/0x830 kernel/softirq.c:576 __do_softirq kernel/softirq.c:610 [inline] invoke_softirq kernel/softirq.c:450 [inline] __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:659 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:unwind_next_frame+0x8d8/0x1d90 arch/x86/kernel/unwind_orc.c:535 Code: 00 48 0f bf 02 48 01 c7 48 89 7c 24 08 4d 8d 7e 01 43 0f b6 04 2c 84 c0 0f 85 20 0f 00 00 4c 89 fa 48 c1 ea 03 42 0f b6 04 2a <84> c0 0f 85 2c 0f 00 00 41 0f b6 46 01 83 e0 03 ff 24 c5 70 8b 28 RSP: 0018:ffffc90002f3ee08 EFLAGS: 00000a06 RAX: 0000000000000000 RBX: ffffc90002f3eec8 RCX: ffffffff8dfa1d78 RDX: 1ffffffff1d2d406 RSI: ffffffff8e96a016 RDI: ffffc90002f3ff58 RBP: ffffc90002f3ef10 R08: 000000000000000b R09: 000000000000000b R10: dffffc0000000000 R11: fffff520005e7de5 R12: 1ffffffff1d2d406 R13: dffffc0000000000 R14: ffffffff8e96a032 R15: ffffffff8e96a033 arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa6/0xf0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc mm/kasan/common.c:513 [inline] __kasan_kmalloc+0xb5/0xf0 mm/kasan/common.c:522 kmalloc_node include/linux/slab.h:625 [inline] kzalloc_node include/linux/slab.h:749 [inline] __get_vm_area_node+0x119/0x2d0 mm/vmalloc.c:2423 __vmalloc_node_range+0xef/0x8b0 mm/vmalloc.c:3027 __vmalloc_node mm/vmalloc.c:3087 [inline] vzalloc+0x75/0x80 mm/vmalloc.c:3157 alloc_counters+0xcb/0x760 net/ipv4/netfilter/arp_tables.c:659 copy_entries_to_user net/ipv6/netfilter/ip6_tables.c:839 [inline] get_entries net/ipv6/netfilter/ip6_tables.c:1041 [inline] do_ip6t_get_ctl+0xa36/0x1120 net/ipv6/netfilter/ip6_tables.c:1679 nf_getsockopt+0x25e/0x280 net/netfilter/nf_sockopt.c:116 ipv6_getsockopt+0x473/0x2470 net/ipv6/ipv6_sockglue.c:1492 tcp_getsockopt+0x200/0x25a0 net/ipv4/tcp.c:4322 __sys_getsockopt+0x1b0/0x230 net/socket.c:2256 __do_sys_getsockopt net/socket.c:2271 [inline] __se_sys_getsockopt net/socket.c:2268 [inline] __x64_sys_getsockopt+0xb1/0xc0 net/socket.c:2268 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f147c3d3f6a Code: 48 83 ec 10 89 d2 48 63 ff 45 31 c9 6a 2a 45 31 c0 31 c9 e8 d8 99 fb ff 48 83 c4 18 c3 0f 1f 00 49 89 ca b8 37 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 06 c3 0f 1f 44 00 00 48 c7 c2 e8 ff ff ff f7 RSP: 002b:00007ffec4ae80e8 EFLAGS: 00000212 ORIG_RAX: 0000000000000037 RAX: ffffffffffffffda RBX: 00007ffec4ae8170 RCX: 00007f147c3d3f6a RDX: 0000000000000041 RSI: 0000000000000029 RDI: 0000000000000003 RBP: 0000000000000003 R08: 00007ffec4ae810c R09: 0000000000000000 R10: 00007ffec4ae8170 R11: 0000000000000212 R12: 00007f147c61eb80 R13: 00007ffec4ae810c R14: 0000000000000000 R15: 00007f147c61ffc0 Allocated by task 4367: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc mm/kasan/common.c:513 [inline] __kasan_kmalloc+0xb5/0xf0 mm/kasan/common.c:522 kmalloc include/linux/slab.h:607 [inline] kzalloc include/linux/slab.h:738 [inline] ax25_dev_device_up+0x50/0x580 net/ax25/ax25_dev.c:55 ax25_device_event+0x483/0x4f0 net/ax25/af_ax25.c:139 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:391 call_netdevice_notifiers_extack net/core/dev.c:2074 [inline] call_netdevice_notifiers net/core/dev.c:2088 [inline] __dev_notify_flags+0x194/0x300 net/core/dev.c:8917 dev_change_flags+0xe3/0x1a0 net/core/dev.c:8955 dev_ifsioc+0x130/0xd50 net/core/dev_ioctl.c:324 dev_ioctl+0x545/0xe30 net/core/dev_ioctl.c:572 sock_do_ioctl+0x245/0x320 net/socket.c:1161 sock_ioctl+0x4d2/0x710 net/socket.c:1266 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Freed by task 4477: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1710 [inline] slab_free_freelist_hook+0xea/0x170 mm/slub.c:1736 slab_free mm/slub.c:3504 [inline] kfree+0xef/0x2a0 mm/slub.c:4564 ax25_dev_put include/net/ax25.h:302 [inline] ax25_release+0x661/0x870 net/ax25/af_ax25.c:1062 __sock_release net/socket.c:651 [inline] sock_close+0xd5/0x240 net/socket.c:1345 __fput+0x234/0x930 fs/file_table.c:311 task_work_run+0x125/0x1a0 kernel/task_work.c:188 get_signal+0x1222/0x12c0 kernel/signal.c:2672 arch_do_signal_or_restart+0xe7/0x12c0 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Last potentially related work creation: kasan_save_stack+0x35/0x60 mm/kasan/common.c:38 kasan_record_aux_stack+0xb8/0x100 mm/kasan/generic.c:348 insert_work+0x54/0x3d0 kernel/workqueue.c:1366 __queue_work+0x9c5/0xd50 kernel/workqueue.c:1532 queue_work_on+0x124/0x1f0 kernel/workqueue.c:1559 queue_work include/linux/workqueue.h:512 [inline] netdevice_queue_work drivers/infiniband/core/roce_gid_mgmt.c:659 [inline] netdevice_event+0x803/0x900 drivers/infiniband/core/roce_gid_mgmt.c:802 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:391 call_netdevice_notifiers_extack net/core/dev.c:2074 [inline] call_netdevice_notifiers net/core/dev.c:2088 [inline] dev_open+0x106/0x180 net/core/dev.c:1591 bond_enslave+0x1138/0x3c50 drivers/net/bonding/bond_main.c:1959 do_set_master net/core/rtnetlink.c:2577 [inline] do_setlink+0xe90/0x3d60 net/core/rtnetlink.c:2788 __rtnl_newlink net/core/rtnetlink.c:3452 [inline] rtnl_newlink+0x1658/0x1a50 net/core/rtnetlink.c:3574 rtnetlink_rcv_msg+0x844/0xf30 net/core/rtnetlink.c:5684 netlink_rcv_skb+0x1f5/0x440 net/netlink/af_netlink.c:2507 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x774/0x920 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x8ba/0xbe0 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:706 [inline] __sock_sendmsg net/socket.c:718 [inline] __sys_sendto+0x46d/0x620 net/socket.c:2072 __do_sys_sendto net/socket.c:2084 [inline] __se_sys_sendto net/socket.c:2080 [inline] __x64_sys_sendto+0xda/0xf0 net/socket.c:2080 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Second to last potentially related work creation: kasan_save_stack+0x35/0x60 mm/kasan/common.c:38 kasan_record_aux_stack+0xb8/0x100 mm/kasan/generic.c:348 insert_work+0x54/0x3d0 kernel/workqueue.c:1366 __queue_work+0x9c5/0xd50 kernel/workqueue.c:1532 queue_work_on+0x124/0x1f0 kernel/workqueue.c:1559 queue_work include/linux/workqueue.h:512 [inline] call_usermodehelper_exec+0x2e3/0x520 kernel/umh.c:435 kobject_uevent_env+0x681/0x890 lib/kobject_uevent.c:633 driver_register+0x3e2/0x430 drivers/base/driver.c:248 phy_driver_register+0x174/0x270 drivers/net/phy/phy_device.c:3179 phy_drivers_register+0x3b/0xc0 drivers/net/phy/phy_device.c:3199 do_one_initcall+0x272/0x730 init/main.c:1316 do_initcall_level+0x137/0x1f0 init/main.c:1389 do_initcalls+0x4b/0x90 init/main.c:1405 kernel_init_freeable+0x3e9/0x570 init/main.c:1629 kernel_init+0x19/0x1b0 init/main.c:1520 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 The buggy address belongs to the object at ffff888022d8f500 which belongs to the cache kmalloc-192 of size 192 The buggy address is located 80 bytes inside of 192-byte region [ffff888022d8f500, ffff888022d8f5c0) The buggy address belongs to the page: page:ffffea00008b63c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x22d8f flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 ffffea0000813400 0000000600000004 ffff888016c41a00 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 1, ts 6936896968, free_ts 6935588146 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x1bbd/0x1ca0 mm/page_alloc.c:4192 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5501 alloc_page_interleave+0x24/0x1e0 mm/mempolicy.c:2031 alloc_slab_page mm/slub.c:1780 [inline] allocate_slab mm/slub.c:1917 [inline] new_slab+0xc0/0x4b0 mm/slub.c:1980 ___slab_alloc+0x80a/0xdd0 mm/slub.c:3013 __slab_alloc mm/slub.c:3100 [inline] slab_alloc_node mm/slub.c:3191 [inline] slab_alloc mm/slub.c:3233 [inline] kmem_cache_alloc_trace+0x1a5/0x2a0 mm/slub.c:3250 kmalloc include/linux/slab.h:607 [inline] kzalloc include/linux/slab.h:738 [inline] call_usermodehelper_setup+0x8a/0x260 kernel/umh.c:365 kobject_uevent_env+0x65e/0x890 lib/kobject_uevent.c:629 driver_register+0x3e2/0x430 drivers/base/driver.c:248 phy_driver_register+0x174/0x270 drivers/net/phy/phy_device.c:3179 phy_drivers_register+0x3b/0xc0 drivers/net/phy/phy_device.c:3199 do_one_initcall+0x272/0x730 init/main.c:1316 do_initcall_level+0x137/0x1f0 init/main.c:1389 do_initcalls+0x4b/0x90 init/main.c:1405 kernel_init_freeable+0x3e9/0x570 init/main.c:1629 kernel_init+0x19/0x1b0 init/main.c:1520 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1340 [inline] free_pcp_prepare mm/page_alloc.c:1391 [inline] free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317 free_unref_page+0x8f/0x2a0 mm/page_alloc.c:3396 __vunmap+0x8b9/0xa50 mm/vmalloc.c:2628 free_work+0x56/0x80 mm/vmalloc.c:95 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Memory state around the buggy address: ffff888022d8f400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888022d8f480: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc >ffff888022d8f500: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888022d8f580: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff888022d8f600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== ---------------- Code disassembly (best guess): 0: 00 48 0f add %cl,0xf(%rax) 3: bf 02 48 01 c7 mov $0xc7014802,%edi 8: 48 89 7c 24 08 mov %rdi,0x8(%rsp) d: 4d 8d 7e 01 lea 0x1(%r14),%r15 11: 43 0f b6 04 2c movzbl (%r12,%r13,1),%eax 16: 84 c0 test %al,%al 18: 0f 85 20 0f 00 00 jne 0xf3e 1e: 4c 89 fa mov %r15,%rdx 21: 48 c1 ea 03 shr $0x3,%rdx 25: 42 0f b6 04 2a movzbl (%rdx,%r13,1),%eax * 2a: 84 c0 test %al,%al <-- trapping instruction 2c: 0f 85 2c 0f 00 00 jne 0xf5e 32: 41 0f b6 46 01 movzbl 0x1(%r14),%eax 37: 83 e0 03 and $0x3,%eax 3a: ff .byte 0xff 3b: 24 c5 and $0xc5,%al 3d: 70 8b jo 0xffffffca 3f: 28 .byte 0x28